package com.small.util;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.codehaus.jackson.map.DeserializationConfig;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize;
import org.codehaus.jackson.type.JavaType;
import org.codehaus.jackson.type.TypeReference;

import java.text.SimpleDateFormat;

/**
 * @create: xie
 */
@Slf4j
public class JsonUtil {

    private static ObjectMapper objectMapper=new ObjectMapper();
    static {
        //对象的所有字段全部列入
        objectMapper.setSerializationInclusion(JsonSerialize.Inclusion.ALWAYS);
        //取消默认date转换转换timestamps形式
        objectMapper.configure(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS,false);
        //忽略控bean转json的错误
        objectMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS,false);
        //所有的日期格式都统一为yyyy-MM-dd HH:mm:ss
        objectMapper.setDateFormat(new SimpleDateFormat(DateTimeUtil.STANDARD_FORMAT));
        //忽略在json字符串中存在，但在java对象中不存在对应属性的情况。防止错误
        objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES,false);
    }

    public static <T> String obj2String(T obj){
        if(obj==null){
            return null;
        }
        try {
            return obj instanceof String ? (String) obj :objectMapper.writeValueAsString(obj);
        } catch (Exception e) {
            log.warn("解析Obj数据转String出现异常",e);
            return null;
        }
    }
    //带格式化的json转换，更美观
    public static <T> String obj2StringPretty(T obj){
        if(obj==null){
            return null;
        }
        try {
            return obj instanceof String ? (String) obj :objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
        } catch (Exception e) {
            log.warn("解析Obj数据转String出现异常",e);
            return null;
        }
    }

    public static <T> T string2Obj(String str,Class<T> clazz){
        if(StringUtils.isEmpty(str)){
            return null;
        }
        try {
            return clazz.equals(String.class)? (T) str : objectMapper.readValue(str,clazz);
        } catch (Exception e) {
            log.warn("解析String数据转Obj类型出现异常",e);
            return null;
        }
    }

    public static <T> T string2Obj(String str, TypeReference typeReference){
        if(StringUtils.isEmpty(str) || typeReference==null){
            return null;
        }
        try {
            return (T)(typeReference.getType().equals(String.class)?str : objectMapper.readValue(str,typeReference));
        } catch (Exception e) {
            log.warn("解析String数据转Obj类型出现异常",e);
            return null;
        }
    }

    public static <T> T string2Obj(String str,Class<?> collectionClass,Class<?>... elementClasses){
        JavaType javaType=objectMapper.getTypeFactory().constructParametricType(collectionClass,elementClasses);
        try {
            return objectMapper.readValue(str,javaType);
        } catch (Exception e) {
            log.warn("解析String数据转Obj类型出现异常",e);
            return null;
        }
    }
}
